SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26dc8e425ed2da6b9da1452e13e361104a592d6c6c89782e62e0a33ac300fc06' 
  AND token = 'C/yRKb3HAkGglsWyTXEHkQKToiNfLMhIBpPlBRCPOvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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