SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c62a5bd6f3fa93eb2c26ae79e3b022753f98403d6a0634d300a99f9481c0cc3' 
  AND token = 'YPtwIXcCB4PwLwx1h9bR2GGkthKLMcsOw3GYyj70KM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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