SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb65487ce5e10c95e47129b3f389c27fcd925c2f26132b70807303a448ebf834' 
  AND token = 'xQi9WK2VrsJ+6CQr4S73gGWLPpJVB/FN8pzXldLt2CM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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