SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a05c21d9c8a6cadb8bb3c2639881e22f031fe44412d7e9dd74ef02cc82816b3f' 
  AND token = '2+HpiCHgnQA3IIr1j3jcKVK1tBa7py7KqnPcKEzGttE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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