SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f880a90e07e75727b9b8d847f5dec7a164e32ba92ce87dab328bc0515a0afbfc' 
  AND token = 'ZN6Rbar7vm+dFZMp6XnOzNiRJAWHpTIuHYdacWbVsTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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