SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae065b1dcf8d839461a809f5e67bf03924d1c14a83f57e0a931cc348c89b358b' 
  AND token = '38UVYjZ2gvJ1T9htnJS0VDnzpG6u3AoizKBkiSZSBQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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