SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56de86d37083f052a0733be35a9f298f18b5baac674dd371774f169a2f8dd9be' 
  AND token = 'CvG+jk1U42Vyww6/7mMnx8uvKd9TtmFzEVwx5QXqRsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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