SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '464034fd2f6e96375db9758ab52b17f9560491262d47a7bebc1bc99a666a30a4' 
  AND token = 'WyOcflzhd1XqnOYg7DOjFa4wgKbKCcKGr67TUb4EQts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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