SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05b60c566975893bf1e4da080936b8761607e977db13abf0a78403a0a972f0f9' 
  AND token = 'YZmvzapOp70CCMEJAb83I8rxzLBqXvj0eoXsS8lEvV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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