SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d98289357b2398df2d21ffea86d0ef7579736429ebf58b243debfd484a7f086' 
  AND token = 'fNn+Aj+VuuA4V2r/gcQOYL7JGj1wzTKOo3t3f99lEl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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