Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15a1ddc9c5d0df9fd8f1e0fdd1a91ee7f7394c00240cfe9c8802b0bf47e34f1c' 
  AND token = '/LFaFUtcuPr0XxfroeNFBl5Fsux+6aH2ICj0sP23AME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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