SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b3ae1fad48b0171f7265c09e4db0a8d2d066c0449af074fdee90bb03c7406f32' 
  AND token = 'g06fl/3aU9O9SlpQgW1xOPbYsKA5/z8JXcXRu1xI4Do=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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