SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0fee09ed5eebd0de0f545d94f73a0896daec6480eec99af4e82a42eee5adf10' 
  AND token = 'tzfbEtS5ZHtu+JzTepzGqf+fIEOPmG24eWXU604RBFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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