SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dd52e0fe6bc9f8ed61a65a7f99a334cf2ef1651b7957a9e3c291dc5bddb1e666' 
  AND token = '+C7X3uQlzj0bi7eMltCWicslGc1dFDHgAskswe74p1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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