SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'add355b901fc33ce0a2b4ed671fb8e759174cdffc06e141c51e4055f1d97e1ef' 
  AND token = 'HxjyJPvwU4YPvdF7MeNQQWdbtEjauL29AIBalaBuXHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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