SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c19081f4504e16ff76d6f5170f433714e8ad1b2c82e835afb72d3c48bfbca1ec' 
  AND token = 'e4j98ek1wUEnp3GwRNrxxp46JZEH190dm1ZODmTZERE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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