SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41eff857f302efa807545df906873778ef8e23ab4dcf315fb9fc56dcdab018c2' 
  AND token = 'poKv84ajrLZlhCkN9GMTqrsFTm1Y7o3NsdBfYM5wFPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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