SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c409fa0328a578b80dd87b1ee1330152be9e163d438a7da4c1a994cfa20977b' 
  AND token = 'rEz3Vind7PiURNf9SzeXcDPGupT93qlrBppn5QmIBcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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