SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26404defbe2782bed1ed9a72a2796f5ffd84d06f50e268ba4c705358789ee145' 
  AND token = 'JgQjhHxVn6k1uJOFx0YHCAbJDNJPqnvxg/vRgD8gAiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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