SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f43bbf1aaba078e92c1cea17f2ac152cbc0e2dc56e53e31587a2c87aac26f6d' 
  AND token = 'tF0MoqFcY3HSuOYgnFOn8h+zoghwPOX7cAiPTOZ7AkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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