SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c176d489072da57244b16c9e92c9595b05a9879979552e5f8b8659f10a0686e' 
  AND token = 'QaBplNDMwCSKWlvwRFJzO9VrVYzkE1S/HkjdYseaakg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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