SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c30d66985e9542df99ddb70e46af85660b2616aed454366ea329b88c5437457f' 
  AND token = '25edvCQtFeeMLB1wTONJDGVgvRccj92qzaBxPjCjZUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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