SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68ca266b68b9925fd926519394fe4031afcdbc53c77cd284670bd4e15ff665b3' 
  AND token = 'OhI4nW0lTV7mkFmQkBFE1pNtaEXiansK4sQgFy14jBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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