SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ca436280b7327eccc71a4e719e81bc54b42e26401c0d0879b8d7217fee700b5' 
  AND token = 'MCNhWvr37PsJH09qhkpLSow1sS6tj4Ur74wwmsGB4ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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