SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1ff9af92ab6ef9066813f992cda84a72b2de72c1b1091912d2c862126d86dd9' 
  AND token = 'ZNJIbuzAJtkXPid/YO9qZTFi7nGW9iddkCGDLCKvxPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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