SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3418f56d94b75656e041249d865db9280f1cc6d5edc42aa159b03986ab02c37c' 
  AND token = 'VO4SClp1NFA7a5Y2SeBVm1Lwnw5lAU4ACdTjH/2LNPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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