SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0f0ea05e1ef362154845a8f67d2e36d78a7b267fe90dd85c722dea3e2c205fb' 
  AND token = '8JWxc5E3AymO18Hwy1m69lkHyAMAhg4DujhtoZV9qXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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