SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c858571dc09cf1540fc1d1c1f1127acf3689039b83cf437e9b5796dcae8cc728' 
  AND token = 'HOLsCO4OFCnpH7SyHha2XZaUnrOyb7iIvXFsAU2M1Pc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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