SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2397fbb78e7f405d7390032612cba1b6e02f11c1ee15dfb62a12743c398b3de5' 
  AND token = 'dUTYaj8jxRiyjP8ag1yDi10MeMQC6jw+G/suAQ2L6Y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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