SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82061d7189654003016bfaccdbaeb900c5451709180f325f4219a40741238082' 
  AND token = '2fIPPhuxiFkNJjxlwkao8W6YrCh4/LCG7ucd4z4zwiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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