SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4a7d1eb9f9e101aa08ed13f2efc3321b5c2896e80f22b2972b6bd4b25b51da6c' 
  AND token = 'DjyF/KoKpqn/U7H32sRGcX+gmWdFIE7/viAwIBjPOHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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