SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '47c8b5be12007ce9cc5640a0619dfdef9135ed6952b666ac271780934cae9a15' 
  AND token = 'u/seEmWzqUIhORsGj7oyJwzcGTgGsdVeSXA24cycvNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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