SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef2a09a9d5b6440b25eea4f036ceb31f2c4baad6494eef8b1925160c3d4fcf7f' 
  AND token = 'cQJR2DVpUPr6zSGojUCNiGYPCrNgigOphPyvYlBYAs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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