SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5e18a2cd279d1baa67dc56aa57cc8e4ba4cea133c4b3ab9c6f62459eec713503' 
  AND token = 'IdmTpCXPkcYLf0Qrg99zqBmgaaRpVjbiCphtBlGcLRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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