SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '318b14e8a2976b4d498e624e97e0b924a5d79c486898dee11b0f5a0bfb1a5876' 
  AND token = 'xpj/sUerwZJ/hq2Gxd0UwBO7x15FfCpoMyXdPHhx3bY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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