SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'db452ecca21616215f81e1230e74419681762cba499b0b27d9a1faad357df3e6' 
  AND token = 'gvPnzXywW4jxHASvGvJ8A5voQ2XSo1tt85CcP9ZUBIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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