SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cef5e933148023302b31ed1ee67a7fb6e5582c9d822af3f074cb820789db1078' 
  AND token = '8OL816x6S2m0wnLoOogOFuEdxTHSbH9sPcCw9cviSwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}