SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '592f4548b66a58a8474e9611915c7966750082b0b42fb0729cffb173fec853de' 
  AND token = 'SYzVYvmDi3Dm+KJD+QFHjDIehnGPNyhganfWJHAXcXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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