SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3866214a8dea7ac0bde25983dbabf80c250f340644f8cb23a4b094259e63edb' 
  AND token = 'TQVb2iDM/opwyqU81Q+HrM9iNY6Pnv2OYZwxQNg7/aI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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