SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b4a6973f23786525d9b11465dfe165816703f3a2742e52a06764ff538137b130' 
  AND token = 'YCbXfFHodf1O+OKz7JktvxnH/dSGdPLsTl2GN4sRs64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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