SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3704aeef2fc07820d35890b0330a536197d965f39266001cdb1481f13e57e99e' 
  AND token = 'my8Z1SI8R6ICRq8vz1DGfuxb06gt4VYbhzP82paBYFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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