SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a49b8f82ff947947e8d732b3af2248af4f511dde817511c5e09e64363b0076d1' 
  AND token = 'XUSOuSGfctLnIO+Ep4BYp9tCAtx7vpibU4Nbo9M0pmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}