SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fbcb4252bbf385e89d6f00720f26cd2bfd375563ee91e448621d15920c180b0' 
  AND token = 'QzofhGaJ+iEXVO6u5w2sf7qnpRfnCC+jMYpw+3YhFB4=' 
  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"
    }
  }
}