SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fc90c4fca6c006e2a1c6330c4e05377cbb75f15b6580d68c2dabe7dd1dcecf58' 
  AND token = 'aaQMqxn9viIx/iXx+CN/ijPB2S7Y+xvpm6VZ9/Z7TcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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