SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2b449f2dfc6677f16522033ff960eef657213c5ee882664b407c1a22adefd88e' 
  AND token = '1Zau47M5DdxPyJDgv0wXnkkyzQ033zLkjrlnqLmJP0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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