SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66f77776baf182a822d342a7a18133e55492ac69aa3a3a814ceeb07260315f04' 
  AND token = 'QZXXBgL8KRG7SSRIKxn230DdPkpE67IdLQMGK8p1KEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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