SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '14160b4b0058412b3ac5f17b6b12d454e2f5f030f5031d76c5a930cc0deaffc4' 
  AND token = '0/8u/yQ2fTW6LDD25ZJAIvI3uePrP86jETHmO9oh99A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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