SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0098306a47829339ce119ff755b55e42fb5c3784877eec1c8533d8fb065eb74' 
  AND token = 'DX90rlaOFtxQG8cFgUH68z02QPVjUNH5cdZdUwCdh70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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