SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c58c3ceefa3059e64e79665785a862202d28539d327098d5d5120970ec200c00' 
  AND token = 'jqZ2YruCc7bYBPdVgDiRQVevBSg15GJtlZ4SXnC8Oqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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