SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5803515d5fa2812c6ed3b486d7e57309b3d9f08db2b177f349634d02c0821a18' 
  AND token = '25jOX+egGRw3JbSjrL8tb7c6cqF3hBi4/HkrFlFfXDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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