SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd083ff989bb0199add7cc146d8b90aba1c02e70bf7c79e4f2253bb977fba62b8' 
  AND token = 'Q/2p3y7MpXmkhHLJKTONrmix1vxgsTeFiwV/A1IcC2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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