SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ba49a03ecec0d03f84175eb47fc9af34ed968eec4e293df1baf7b3ccaaf8f3f' 
  AND token = 'j51PR2XuauW5norpGX41li+s62HwuUfdQdXoiJML3Fc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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