SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '906b258a282ebd2cf594551bd785d77dbb77b5396aeece47dde21d644042b184' 
  AND token = 'U6/0fn4OFM8ZZSkrw8yRKGqyugJSOW85YVugFh0YrO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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