SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a1b7e22f58105d237cdfa9de6e4ebe939752ff3a18d98dc0587af7e4cf3f1ed0' 
  AND token = 'nXtV80OHrjNlpYmvbvZuTNZQ4wAeA7chGeszx0akgVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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