SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2eea7c7d60398fba369bb0a702f61108e0ef342fc2ac8c16bc61b20b1bf90999' 
  AND token = 'gDTnxByamBVXTUv8+aUATORjMqcmz/kFVEldOL8AFow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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