SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46ac5ad7c4f6c25f6baaecff0b9098410dde797da38f2d91d91c6641ef178080' 
  AND token = 'NvbKPHrEwXCiRHhR9V12edf/BDBwKkDYK76NNZWdDMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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