SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9cd662eb330c8c1e4710ed78397b863eacab11e145335800f8cdef0678bb6ad' 
  AND token = 'Aq/NUO6qWkmik5gvWkSjSxYWG8O6GVo0isJp1drFdDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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