SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df9218d34d16d36d0ab33312def97f6aa19b94b2d91940234e97ce8ebcf17b76' 
  AND token = '7xYSztJB1UhD6Ad9oF5+B4JiH/H1XmnIxzfqQ6ggEQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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