SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4127f1e3715c909f8292622e7529f14ca6df395c7fe2f8eb3f346115dfdb8915' 
  AND token = 'UHkrem8V5eFA1NoVV8Le/g+caZVKrLBv8krecD8JAMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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