SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db0345f2090bcd9c71f9c67b514558b67c9b5dfa6df59d0e9bc939215208e495' 
  AND token = 'er1/mprBu85XPKfKu7jajQgbc1DiFSJNe9xzUdPQufQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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