SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1c3933f9abbfcc9778aed3a20d3cf6d294f36eba6b882e41da14ece403e00c72' 
  AND token = 'ETAJQIeuFcok4tGowzhoLlXyUhYNxmwbRls/1a9yVCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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