SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '371f74306a33c2d5fa5e4f96b0db6177c905a91f04f713ef4cabd916bebb1805' 
  AND token = 'kM0mjapJOBTJaflNZxnqKyEOhruEBsT4riNTUXI5LCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}