SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfd92328ec1cd00da217d03c6d725a42f7ba528200ea543c98d6668bf5849896' 
  AND token = '63yGV3rPkF2Vbnmxuw5ZIiZ6LY0xdCltyudRh9SSn5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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