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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4e28a100cbc13d1a6a2d2ad03126528de61ead66c20f40a54c29f734e9fdb99' 
  AND token = 'MDnEg7nlx9pDgWtf9xZFjOWLsOa3zyMXoB6bWo/NL+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}