SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cc9e88a8c4a08d3eccf25addf09d14d2088fca30445b19226845163ce32bc912' 
  AND token = 'aDFot/aiBMQeagsbx3YeIft5rMPcTapdcGxTiT76mOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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