SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b23a2b976ea466a2bfeafa261bac844628b769082ec554867d24fb2d0b742e0c' 
  AND token = 'dRjdlhHgIAxfpiyJCwQs/Crqxsfmil4uLWWj8+NH89U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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