SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31674d7fbce080855689530b6b6377144b470d6fe52848445073260f53419fa3' 
  AND token = 'hDIQj0NLzqpTSCJ+YjgvABPmf0CvGGk2xKoFkkMDLiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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