SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e96396f26f8c89bdc64e6ec19056becd00554aa51c898979d517c5b5cffae6b' 
  AND token = 'MH8rfihHWW+Xfow/en0lbznvQ6TQP4ImdMxVZ3ubqJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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