SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f36743531b414c397255c5c8915733b0902f42e68ca97f32deae18103dda6ca' 
  AND token = 'wVeUC6Ra5vvX92YjM+3SQaslP03g+hgGCo//wwQtmEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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