SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ac3a0506474ef14fa9ac2607a81a473c53cc2ed274d3be07e18d0a6c010f57ce' 
  AND token = 'lvQFCR2TKTJyJYy22E9JoTEaWo61oTqHZIK3h0x3UMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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