SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '35346c06c1116fa0746d0ec58e0b923b9123bce953571f2e2b2f602d78f6fd54' 
  AND token = 'Ij17wSR4mYZsI1rQlK/OUHqNgNUQofee+upjDxQHbIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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