SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40bb3d2fdc2afa0a9e09d70bc2b468dc1c201e4f378d4b959f48da38a802b4ce' 
  AND token = 'pM2P3P8jzJdVr4a0QjTjYhSo1tLN9WPvedzfeMNkIf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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