SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aeaaf311e1d2cb9969c9c00377794d29aadb675f25e785e0e63f45a26c98b027' 
  AND token = 'JF5pP/mQIWP5ksiC2541tYlirTvqluPt6g51gShkQvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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