SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4825b9d30dc7fe3c0a83a94f9b139c25cbaad198f39fff7b8263c5171bd0172' 
  AND token = 'JMLOT1lYybC7inFUkqoS/CVq4SkaEeDHpkchofu3uAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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