SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a865c0dfc62794da69d6aed1bc4b9b5594da028ce32d7fd2bef89df399c64564' 
  AND token = 'aAqxUUvvYZPtM91s9Fc5rQ3jzjAav/y1fOX0ojB4JSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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