SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f03b576f337fff761c5ec652292920e83e00776d8ce68dd6508b2d4e4c56264' 
  AND token = 'IlKAGGGqS/Th9jSPjHRPY3OeVW+iY+5DygT3u+peJ+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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