SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd213028e899bab11492e925a91d66042d03c0c7384619e7f980c8fe91aa556f' 
  AND token = 'NDBUlLlQHnGs6Cmpi+HQ5wQHq1Z/ngF+wBVKBkwPgi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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