SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'db0f63bf98530af2fde9b9b5dd9046aeb50f88b1e259762652110e935691dd0c' 
  AND token = 'Srp5NTpNkj+uXssNDJWhKopDFoVMSg2+QYx/+E/cYdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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