SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e78d2cee5af1d2192f9a18ec5532beeafa1c3c20ec08e034a70dc8c074443cfc' 
  AND token = 'aB8ZcY/2nCnXJK6QZb8c6xgNFVrcjBaqmkrVi8GuAFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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