SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '85f6420143e77420308bd7f18f1d3828ccfbc1bc378a6b95f05a13303af7b844' 
  AND token = 'i4LgYBddxAmj/uSyQF6WmJnLEcbEx/nPKZprIeUy5hM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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