SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f0c4419edbff4638fa2a55c9116f53da4b09d68a220a9850315bbfec4b24f8b6' 
  AND token = '9VKwFZsmgNiJKAGlmFfBPb+lp8bsRpRLAOMBRnJMufA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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