SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d678d5384b09cd4439429ac75176b0485333399b958c6efe2a5cac98809b550' 
  AND token = 'V+NDdsT1NAVYYUFxr7y1iwEPOWahcmURp/CORaykE2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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