SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '552e097aa9824781f1e1b2fd3e2208f3652e3d65cba9241940fda482bcbbec5e' 
  AND token = 'jlbrPohStBAkCQM53H8GZmIAMNFrEt/Nfl9vq/eUjtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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