SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee43e0558263ce51e9d46f12de982295671f98cdd5d61e93d19bb549e2f0cfc1' 
  AND token = '5SV5zQS0xqec8Yi/X9rCWuYFVmi81sKZuxaJ9RyB9nM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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