SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ab802baf6872436e760f379b1c58d1224c723f069a52f735eea847bac7ea8c8' 
  AND token = 'WqwGXNL7YcEqH1p+5JYX8FBDtcy9txdkkyNalokcWa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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