SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3a0ecb06179d441d123269c5721c348682a09784128e9a9b1764541b97c51a5d' 
  AND token = 'XbKBpBy6nPNW4wOYwEclWNvpQ/uU8PKEegVFOfCFmHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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