SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cabc4b6e9fef47dfb00985f01d4fea7f6bfbdfa88268d2937ad115e0565f7591' 
  AND token = 't0Kc1shKJiQO+nICH9i3lKuRIkJykh2lG3Fh9Y9mck8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}