SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '121483f045d54fe12848be00c3405cab5d0acffd94fa66bc4f797ff07829399a' 
  AND token = 'BaYVN2+q8paXjG3xfRU1wjnysIiKdVOh06EdmoglVhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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