SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e7286f982df02299b7e1e0d64a3a7d824bed8dc0070e2e85f83d7adfa61cae1' 
  AND token = 'jfifEXknY03Pv9oknGlRqG3gD87uUxgRylWrgrUAfTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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