SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee8d4db2f39bfdc9b8be071d1905b2888858dd2a0fcc1e61204a4c58a2fdb7c7' 
  AND token = 'nMs/Y3jZApWAC/31My+MyjgZjY4MMJha+ievfrj6aIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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